With advancement and development of cellular phones and other portable information devices, there has been high demand for alkaline dry batteries that are capable of discharging under a heavy load.
Some techniques proposed to attain the enhanced discharge characteristic of the alkaline dry battery under a heavy load add titanium oxide in anatase form (for example, JAPANESE EXAMINED PATENT PUBLICATION No. 8-510355), a complex oxide mainly composed of titanium oxide (for example, JAPANESE LAID-OPEN PATENT PUBLICATION No. 9-139201), or a barium compound like barium sulfate (for example, INTERNATIONAL PUBLICATION No. WO 00/30198) as an additive for the positive electrode.
Addition of titanium oxide, the complex oxide mainly composed of titanium oxide, or the barium compound to the positive electrode improves the discharge characteristic under a heavy load to some extent. Such addition, however, does not ensure the utilization rate of the active material sufficiently. These conventional additives require a large amount to be used for the sufficient effects. Addition of a large amount, however, undesirably lowers the amount of manganese dioxide as an active material filled in the positive electrode, thus decreasing the electric capacity of the battery and causing some deterioration of the discharge characteristic under a light load. The alkaline dry batteries are applied to devices that require discharge under a light load, such as clocks. Deterioration of the discharge characteristic under a light load is accordingly undesirable.